This article addresses the factors that affect the public response to a warning message and the processes that individuals are likely to go through before responding. These factors include obtaining confirmation of the warning from alternative sources; contacting friends and family; individual recipient characteristics; and features of the message itself (e.g. clarity, consistency). Individuals are unlikely to obediently follow all instructions, but much can be done to persuade them to take appropriate action.
Immediate public response
A warning issued from the authorities about an incident does not directly stimulate public action. Instead it involves an intervening process of perception formation and interpretation that is affected by a number of factors including risk perception, warning style and a variety of social factors. The research indicates that individuals consider these impacts and then act, rather than engaging in action that result in social chaos, looting, panic, immobilisation due to emotional shock or, conversely, docile obedience to authority [7,74].
Recipients of warning messages rarely respond to the initial message. In fact, disbelief of the first message is common and this instigates attempts to confirm the threat from other sources and to gather further information. This response process is termed ‘milling’ and is particularly likely when the disaster is unexpected and the level of emergency preparedness is low . However, rather than grounded in denial, this response is likely to be a rational disbelief of improbable events in unusual and confusing situations. People will therefore respond to the social cues around them, i.e. what they can see happening and the actions of others, with the warning message being enhanced or undermined by those around them . Individuals are also likely to contact friends and family to discuss the situation and come to decisions based on these social ties.
Such social considerations can have significant impacts on behaviour. In one example, it was found that as family cohesion increased so did the likelihood of responding to an evacuation warning . It is also suggested that unless the actions of family members are accounted for (if thought to be in the affected area) then individuals may not respond sufficiently to a warning message . This has important implications for enabling communication between distributed family members and in particular those living alone during an incident.
A warning message is most likely to be timely and effective if it creates the perception that a threat is certain and will lead to severe and immediate consequences for the recipients . Indeed, in a study of inhabitants surrounding Three Mile Island, it was noted that the most frequently cited reasons for leaving the area were the warnings from the authorities and the belief in a real situational danger .
It is important therefore, for warning messages to give clear details of the hazard, affected location and relevant timescales, as well as guidance about what to do. Clarity of these issues should avoid potential conflicts caused by different channels of warning that can result in, for example, information accurate for one geographical area being received and acted upon in another area, or differences in updating information by different sources causing reception of out-of-date information [74,79].
It is also important that the source of the warning message is perceived to be credible and trustworthy. Information from credible and reliable sources encourages believability and thus is more likely to result in action . Furthermore, since people have different views about who is credible and who is not, information from a variety of sources (as long as it is consistent) can increase believability consensus [7,81].
The perception of a real threat can be conveyed not only through message content, but also by message style. A warning message is more likely to be heeded if the message is specific, consistent, certain and accurate. Even if specificity is not possible on all content, the warning message itself need not be non-specific and the message can be certain about actions, even if there is ambiguity about impacts. Moreover, perceived accuracy is enhanced by simply being fully open and honest with the public from the outset .
Other influencing factors
Individual recipient characteristics can also have an impact on responses to a warning message. For example, it has been suggested that preconceived ideas of an emergency can impact situational perceptions of risk. If their perceptions of the hazard are inaccurate, people may disregard warnings or respond unnecessarily . Moreover, people who have erroneous beliefs about protective actions may fail to comply with official warnings . It has also been suggested that prior experience of a disaster engenders greater preparedness for subsequent incidents , but that risk perception of a specific incident is unrelated to prior experience. Individuals’ protective response to warnings are a consequence of the perceptions they form immediately prior to taking action [7,74]. It is unlikely, however, that members of the public would have had prior experience of a CBRN or similar scale incident.
A number of factors therefore influence the response to a warning message. It is believed that individuals will behave rationally, but will not comply automatically with the warning message. The warning message needs to be clear and detailed. People are information hungry in such an event, and it is a myth that warnings should be short . If possible, warning confirmation should be offered through telephone/Internet hotlines . Consideration should also be given to individuals who will want to contact family and friends to confirm warning messages, well-being and potential responses.
It is also possible that sub-groups within the affected area will respond differently. For example, tourists in an affected area are much less likely to receive a direct warning and are also more likely to completely ignore a warning or simply leave the area (although they still show the need to confirm the warning message) . Although studies focusing specifically on racial and ethnic factors in disaster response are rare it is noted that such differences could influence a wide range of perceptions and behaviours, including threat perception, concern about hazards, understanding and belief in the science underlying hazard information, and attitudes towards the agencies disseminating information . Family and social structures within different communities may also affect the response to warnings.
A cross-cultural study of reactions to (fictional) warnings about a hazardous chemical incident in Greece, France and the Netherlands found that in France and the Netherlands the greatest degree of belief in the warning message was following the official warning, but this was not the case in Greece . The difference was explained by a large degree of scepticism in the Greek population toward official warnings. However, the significant point is that different groups can react differently to the same warnings.
While it is the case that individuals are unlikely to obediently follow all warnings and instructions given to them, the authorities can do much to persuade them to take appropriate action. Clarity and accuracy of messages and awareness of the social nature and concerns of the population can help to ensure that warnings are heeded.